U.S. patent application number 15/930313 was filed with the patent office on 2020-11-19 for single piece droplet generation and injection device for serial crystallography.
The applicant listed for this patent is Jorvani Cruz Villarreal, Diandra Doppler, Sahir Gandhi, Daihyun Kim, Richard Kirian, Reza Nazari, Alexandra Ros. Invention is credited to Jorvani Cruz Villarreal, Diandra Doppler, Sahir Gandhi, Daihyun Kim, Richard Kirian, Reza Nazari, Alexandra Ros.
Application Number | 20200363348 15/930313 |
Document ID | / |
Family ID | 1000004827739 |
Filed Date | 2020-11-19 |
United States Patent
Application |
20200363348 |
Kind Code |
A1 |
Ros; Alexandra ; et
al. |
November 19, 2020 |
SINGLE PIECE DROPLET GENERATION AND INJECTION DEVICE FOR SERIAL
CRYSTALLOGRAPHY
Abstract
A single-piece hybrid droplet generator and nozzle component for
serial crystallography. The single-piece hybrid droplet generator
component including an internally-formed droplet-generation
channel, an internally-formed sample channel, a nozzle, and a pair
of electrode chambers. The droplet-generation channel extends from
a first fluid inlet opening to the nozzle. The sample channel
extends from a second fluid inlet opening to the droplet-generation
channel and joins the droplet-generation channel at a junction. The
nozzle is configured to eject a stream of segmented aqueous
droplets in a carrier fluid from the droplet-generation channel
through a nozzle opening of the single-piece component. The pair of
electrode chambers are positioned adjacent to the
droplet-generation channel near the junction between the
droplet-generation channel and the sample channel. The timing of
sample droplets in the stream of fluid ejected through the nozzle
is controlled by applying a triggering signal to electrodes
positioned in the electrode chambers of the single-piece
component.
Inventors: |
Ros; Alexandra; (Phoenix,
AZ) ; Kim; Daihyun; (Mesa, AZ) ; Doppler;
Diandra; (Scottsdale, AZ) ; Cruz Villarreal;
Jorvani; (Tempe, AZ) ; Kirian; Richard;
(Tempe, AZ) ; Nazari; Reza; (Tempe, AZ) ;
Gandhi; Sahir; (Tempe, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ros; Alexandra
Kim; Daihyun
Doppler; Diandra
Cruz Villarreal; Jorvani
Kirian; Richard
Nazari; Reza
Gandhi; Sahir |
Phoenix
Mesa
Scottsdale
Tempe
Tempe
Tempe
Tempe |
AZ
AZ
AZ
AZ
AZ
AZ
AZ |
US
US
US
US
US
US
US |
|
|
Family ID: |
1000004827739 |
Appl. No.: |
15/930313 |
Filed: |
May 12, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62847729 |
May 14, 2019 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2223/30 20130101;
G01N 23/20008 20130101; G01N 23/207 20130101 |
International
Class: |
G01N 23/20008 20060101
G01N023/20008; G01N 23/207 20060101 G01N023/207 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with government support under R01
GM095583 awarded by the National Institutes of Health and under
1231306 awarded by the National Science Foundation. The government
has certain rights in the invention.
Claims
1. A droplet generator system for serial crystallography comprising
a single-piece component including an internally-formed
droplet-generation channel extending from a first fluid inlet
opening to a nozzle of the single-piece component; an
internally-forming sample channel extending from a second fluid
inlet opening to the droplet-generation channel, wherein the sample
channel joins the droplet-generation channel at a junction; the
nozzle configured to eject a stream of segmented aqueous droplets
in a carrier fluid from the droplet-generation channel through a
nozzle opening of the single-piece component; and a pair of
electrode chambers positioned adjacent to the droplet-generation
channel near the junction between the droplet-generation channel
and the sample channel.
2. The droplet generator system of claim 1, wherein the
single-piece component further includes the first fluid inlet
opening positioned on an exterior surface of the single-piece
component; and the second fluid inlet opening positioned on the
same exterior surface of the single-piece component as the first
fluid inlet opening, wherein the sample channel includes a curved
section configured to redirect a fluid flow towards the
junction.
3. The droplet generator system of claim 1, wherein the
single-piece component further includes a pressurized gas channel
extending from a gas inlet opening position on an exterior of the
single-piece component to an internal chamber of the nozzle.
4. The droplet generator system of claim 3, wherein a distal end of
the droplet-generation channel is positioned in the internal
chamber of the nozzle proximate to the nozzle opening such that
fluid leaving the droplet-generation channel is expelled through
the nozzle opening as a jetted stream coaxially with a pressurized
gas received in the internal chamber of the nozzle.
5. The droplet generator system of claim 1, further comprising a
pair of electrodes, wherein each electrode is positioned in a
different electrode chamber of the pair of electrode chambers.
6. The droplet generator system of claim 5, wherein, when a sample
fluid is supplied to the single-piece component through the sample
channel and an oil fluid is supplied to the single-piece component
through the droplet-generation channel, the sample fluid flows with
the oil fluid at the junction as a sequence of sample fluid
droplets in a stream of oil fluid.
7. The droplet generator system of claim 6, further comprising a
signal generator configured to apply a triggering signal to the
pair of electrodes, wherein the triggering signal applied by the
electrodes controls a timing of the sample fluid droplets moving
through the droplet-generation channel towards the nozzle.
8. The droplet generator system of claim 1, wherein the
single-piece component is selected from a group consisting of a 3D
printed component and an injection molded component.
9. A method of operating the droplet generator system of claim 1
for serial crystallography, the method comprising: controllably
providing a sample fluid to the single-piece component through the
first inlet opening at a first flow rate; controllably providing an
oil fluid to the single-piece component through the second inlet
opening at a second flow rate, wherein the sample fluid flows with
the oil fluid at the junction as a sequence of sample fluid
droplets in a stream of the oil fluid; adjustably controlling a
frequency of sample fluid droplets in the stream of oil fluid by
adjusting the first flow rate and the second flow rate; and
synchronizing a timing of the sample fluid droplets with a pulse
timing of a laser for serial crystallography by applying a
triggering signal to electrodes positioned in the electrode
chambers of the single-piece component.
10. A droplet generator system for serial crystallography
comprising: a 3-D printed, single-piece component including a first
fluid inlet opening positioned on an exterior of the single-piece
component, a second fluid inlet opening positioned on the exterior
of the single-piece component, a gas inlet opening positioned on
the exterior of the single-piece component, a fluid
droplet-generation channel formed internally and extending from the
first fluid inlet opening to a nozzle of the single-piece
component, a sample channel formed internally and extending from
the second fluid inlet opening to the fluid droplet-generation
channel, wherein the sample channel joins the fluid
droplet-generation channel at a T-junction, a gas channel formed
internally and extending from the gas inlet opening to the nozzle,
the nozzle junction configured to receive a pressurized gas from
the gas channel and a fluid from the droplet-generation channel,
and eject the fluid coaxial with the pressurized gas through a
nozzle opening of the single-piece component, and a pair of
electrode chambers formed internally and positioned adjacent to the
droplet-generation channel near the T-junction; a pair of
electrodes, wherein each electrode of the pair of electrodes is
positioned in an electrode chamber of the pair of electrode
chambers; an oil fluid supply system coupled to the first fluid
inlet opening and configured to supply an oil fluid to the
single-piece component; a sample fluid supply system coupled to the
first fluid inlet opening and configured to supply an oil fluid to
the single-piece component; a pressurized gas supply system coupled
to the gas inlet opening and configured to supply the pressurized
gas to the single-piece component; and an electronic controller
configured to generate control signals to the oil fluid supply
system and the sample fluid supply system to controllably regulate
a rate at which the sample fluid and the oil fluid are pumped into
the single-piece component, wherein the sample fluid flows with the
oil fluid at the T-junction as a sequence of sample fluid droplets
in the oil fluid stream, and controllably regulates an electrical
signal applied to the droplet-generation channel by the electrodes
to adjust a timing at which the sample fluid droplets are ejected
through the nozzle opening of the single-piece component.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 62/847,729, filed May 14, 2019 and entitled
"DROPLET GENERATION AND INJECTION FOR SERIAL CRYSTALLOGRAPHY," the
entire contents of which are incorporated herein by reference.
BACKGROUND
[0003] The present invention relates to systems and methods for
crystallography. More specifically, this invention relates to
systems and methods for generating a sample stream for serial
crystallography.
SUMMARY
[0004] Serial femtosecond crystallography (SFX) is used to
determine the structure of macromolecules at ambient temperature
and, in some implementations, enables the study of large membrane
protein complexes at atomic resolution and reaction dynamics of the
same, which was generally unable to be done using traditional
crystallographic methods. In SFX experiments with X-Ray fee
electron lasers (XFELs), sample crystals are positioned in the beam
of the XFEL. Each crystal hit by the XFEL is destroyed and the
sample needs to be replenished between X-ray pulses. In some
implementations, this is accomplished by a continuous injection of
crystal suspension. Large amounts of sample are required to collect
a complete X-ray diffraction data set for high-resolution crystal
structures. Additionally, any crystal samples delivered in the path
of the X-ray beam during its "off-time" (i.e., time between pulses)
is wasted due to the intrinsic pulsed nature of XFELs. In some
cases, up to one gram of protein may be required for the continuous
injection stream and, of that one gram, up to 99% of the protein is
wasted between pulses. Accordingly, in some cases, sample
preparation constitutes a major limiting factor for SFX with
XFELs.
[0005] In some implementations, a device for use in a hybrid
droplet generator includes a first channel, a second channel, a
third channel, and an outlet passage. The second channel is in
communication with the first channel via a junction. The outlet
passage is disposed downstream from the junction. The third channel
is in communication with the outlet passage. The device also
includes electrodes that are coupled to the outlet passage. The
electrodes are configured to provide an electric current to a
stream of segmented aqueous droplets in a carrier fluid flowing
through the junction.
[0006] In other embodiments, a device for use in a hybrid droplet
generator includes a first channel, a second channel, a third
channel, and electrodes. The second channel is in communication
with the first channel via a T-junction. The third channel is
concentric with the first channel and in communication with the
first channel and the second channel downstream of the T-junction.
The electrodes are coupled to at least one of the first channel and
the second channel. The electrodes are configured to provide an
electric current to a stream flowing through the junction.
[0007] In one embodiment, the invention provides a single-piece
hybrid droplet generator and nozzle component for serial
crystallography. The single-piece hybrid droplet generator
component including an internally-formed droplet-generation
channel, an internally-formed sample channel, a nozzle, and a pair
of electrode chambers. The droplet-generation channel extends from
a first fluid inlet opening to the nozzle. The sample channel
extends from a second fluid inlet opening to the droplet-generation
channel and joins the droplet-generation channel at a junction. The
nozzle is configured to eject a fluid from the droplet-generation
channel through a nozzle opening of the single-piece component. The
pair of electrode chambers are positioned adjacent to the
droplet-generation channel near the junction between the
droplet-generation channel and the sample channel. The timing of
sample droplets in the stream of fluid ejected through the nozzle
is controlled by applying a triggering signal to electrodes
positioned in the electrode chambers of the single-piece
component.
[0008] Other aspects of the invention will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of a sample injection system for
serial crystallography.
[0010] FIG. 2 is a block diagram of a control system for the sample
injection system of FIG. 1.
[0011] FIG. 3A is a schematic diagram of serial crystallography
system including the sample injection system of FIG. 1.
[0012] FIG. 3B is a schematic diagram of a triggering operation for
synchronizing sample droplets in the output stream generated by the
sample injection system of FIG. 1 with the laser beam pulses in the
serial crystallography system of FIG. 3A.
[0013] FIG. 4A is a perspective view of a single piece droplet
generation and injection device for the sample injection system of
FIG. 1 showing a rear surface and a first side surface of the
device.
[0014] FIG. 4B is another perspective view of the single piece
device of FIG. 4A showing the first side surface and a front
surface of the device.
[0015] FIG. 4C is yet another perspective view of the single piece
device of FIG. 4A showing the rear surface and a second side
surface of the device.
[0016] FIG. 4D is a partially transparent overhead view of the
single piece device of FIG. 4A.
[0017] FIG. 5A is an elevation view of the rear surface of the
single piece device of FIG. 4A.
[0018] FIG. 5B is a first cross-sectional overhead view of the
single piece device of FIG. 4A.
[0019] FIG. 5C is a second cross-sectional overhead view of the
single piece device of FIG. 4A.
DETAILED DESCRIPTION
[0020] Before any embodiments of the invention are explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangement
of components set forth in the following description or illustrated
in the following drawings. The invention is capable of other
embodiments and of being practiced or of being carried out in
various ways.
[0021] FIG. 1 illustrates an example of a sample ejection system
100 that provides for controlled generation of a stream of
segmented aqueous droplets in a carrier fluid and ejection of a
stream. For example, the system 100 may be configured for
"water-in-oil" droplet generation of a crystal sample (suspended in
a fluid media) as a sequence of droplets in a stream of oil fluid
in order to inject the aqueous droplets with the sample into an
X-ray beam for serial crystallography. The system 100 also includes
an electrode configuration in order to controllably synchronize the
flow of droplets with the pulse rate of the X-ray beam.
[0022] The system 100 of FIG. 1 includes a first fluid channel 101
and a second fluid channel 102. The first fluid channel 101
includes a pump 105, a flow rate sensor 107, and a sample reservoir
109. The pump 105 is operated to move fluid from the sample
reservoir 107 through the first fluid channel 101. By monitoring
the output of the flow rate sensor 107 and using the output of the
flow rate sensor 107 as control feedback, the pump 105 can be
adjusted to controllably regulate the rate of fluid flow from the
sample reservoir 109. In some implementations, the sample reservoir
109 may further include a shaker or cooler mechanism for preparing
and/or maintaining the sample before it is pumped through the first
fluid channel 101. The second fluid channel 102 similarly includes
a pump 111, a flow rate sensor 113, and an oil reservoir 115. The
pump 111 is controllably operated based on an output signal of the
flow rate sensor 113 to control the rate at which fluid is pumped
from the oil reservoir 115 through the second fluid channel
102.
[0023] In some implementations, the sample reservoir 109 is
configured to hold a volume of a crystal sample suspended in an
aqueous fluid (e.g., water) and the oil reservoir 115 is configured
to hold an oil. The fluids from each of the two fluid channels 101,
102 are pumped towards a T-junction 117 where they are combined in
the same output channel as a stream of segmented aqueous droplets
in a carrier fluid (as described further below) towards a nozzle
119. In some implementations, the nozzle 119 is a gas dynamic
virtual nozzle (GDVN) configured to receive pressurized helium gas
from a pressurized helium gas source 121. In some implementations,
the system 100 also includes a controllable pneumatic valve 123 to
regulate a flow rate of the pressurized helium gas from the source
121 and a pneumatic flow rate sensor 125 to measure the actual
pneumatic flow of helium gas towards the nozzle 119 so that the
position of the controllable valve 123 can be adjusted towards a
target pneumatic flow rate. The nozzle 119 is configured to emit
the combined fluid stream and the pressurized helium gas coaxially
with the combined fluid stream at the center of the pressurized
helium gas flow, which results in a "jetting" of the fluid output
stream.
[0024] By controlling the flow rate of the sample suspension fluid
(through the first fluid channel 101) and the flow rate of the oil
(through the second fluid channel 102), the system can be operated
to controllably introduce the sample suspension fluid into the oil
stream as a series of droplets. As described in further detail
below, an electrode configuration (i.e., electrodes 127) is
positioned and configured to apply an electrical signal to the
fluid stream that effectively regulates the position, sequence, and
synchronization of the sample droplets in the output fluid stream
that is ejected from the nozzle 119. In some implementations, the
electrodes 127 are configured as "non-contact electrodes" that do
not physically contact the fluid stream and may be made from
gallium, silver, or another suitable material. The electrodes 127
induce local electric fields that change the water-in-oil interface
and trigger the change of droplet generation frequency.
[0025] FIG. 2 illustrates an example of a control system for the
system 100 of FIG. 1. A controller 200 includes an electronic
processor 201 and a non-transitory, computer-readable memory 203.
The memory 203 stores data and computer-executable instructions
that are accessed & executed by the electronic processor 201 to
provide the functionality of the controller 200 (including, for
example, the functionality described herein). The controller 200
may be implemented, for example, as a desktop computer system or as
an application-specific system.
[0026] The controller 200 is communicatively coupled to the pump
105 of the first fluid channel 101, the pump 111 of the second
fluid channel 102, and the controllable pneumatic valve 123 and
provides control signal that regulate/adjust the operation of these
components. The controller 200 is also communicatively coupled to
the flow rate sensor 109 of the first fluid channel 101, the flow
rate sensor 115 of the second fluid channel 102, and the pneumatic
flow rate sensor 125. Accordingly, in some implementations, the
control 200 operates the system 100 to achieve target fluid flow
rates in the first fluid channel 101 & the second fluid channel
102 and to provide a target pneumatic flow/pressure of the helium
gas provided to the nozzle 119 by adjusting the control signals
provided to the pump 105, the pump 111, and the controllable valve
123 based, at least in part, on the sensor signals received from
the flow rate sensors 109, 115, 125. The controller 200 is also
communicatively coupled to a trigger signal generator 205 that is
configured to generate a trigger signal that is applied to the
trigger electrodes 127 in order to controllably regulate the
droplet generation frequency of the system 100.
[0027] Furthermore, although FIG. 2 illustrates only a single
controller 200, in some implementations, a plurality of controllers
may be configured to provide the functionality and processing for
the system 100. For example, in some implementations, a separate
controller is implemented to regulating the pneumatic components
independently from the droplet generation functionality. In some
such implementations, the controllable valve 123 and the pneumatic
flow rate sensor 125 are communicative coupled to a separate
controller, which is configured to provide for pneumatic control
and to regulate a gas mass flow rate in order to establish a
properly formed "jet" from the nozzle, but does not provide any
functionality related to droplet generation and triggering.
[0028] FIG. 3A illustrates an example of the operational
configuration of the sample ejection system 100 for serial
crystallography. The sample ejection system 100 is controllably
operated to eject a jetted fluid stream 301 through the optical
path of an x-ray laser beam 303. The x-ray laser beam 303 is
generated by a laser source 305 and diffraction of the x-ray laser
beam 303 caused by the sample in the output stream 301 is captured
by an imaging sensor 307. One or more electronic controllers 309
are communicatively coupled to the sample ejection system 100, the
laser source 305, and the imaging sensor 307 to control the
characteristics of the output stream 301 as well as receiving and
processing image data from the imaging sensor 307 in order to
determine a molecular structure (and, in some cases, other
properties) of the sample crystal in the output stream 301. In some
implementations, the electronic controller 309 (or a different,
separate electronic controller) is configured to operate the x-ray
laser beam 303 (e.g., controlling the on/off status of the laser
source 305) and/or to receive information from the laser source 305
regarding the pulse timing of the laser beam 303.
[0029] As described above, the system 100 of FIG. 1 is controlled
to produce an output stream 301 that includes a series of droplets
in an oil fluid. The droplets include a crystal sample suspended in
an aqueous medium (e.g., water). The droplets are introduced into
the oil fluid stream at the T-junction 117 and certain
characteristics of the droplets (including, for example, the size,
frequency, etc.) can be controlled in part by adjusting the flow
rate of the sample suspension and the oil fluid using pumps 105,
111. The properties of the crystals in the sample are determined by
analyzing diffraction data of the x-ray laser beam interacting with
the output stream 301. However, useful diffraction data is only
obtained when the laser beam is diffracted by one of the sample
suspension droplets. Sample droplets passing through the optical
path of the x-ray laser beam 303 when the x-ray laser beam is
between pulses are effectively wasted as they produce no useful
diffraction data. Accordingly, the trigger electrodes 127 are
controllably operated to apply an electrical signal to the stream
of "water-in-oil" droplets at or near the T-junction 117.
[0030] FIG. 3B illustrates one example of the electrode-based
triggering for synchronizing the droplet flow with the x-ray laser
pulse. FIG. 3B shows the oil fluid stream 313 with a series of
droplets 315A, 315B, 315C, 315D. A schematic example of the x-ray
laser pulse signal 317 is illustrated adjacent to the water-in-oil
stream. As shown in FIG. 3B, the first two droplets 315A, 315B are
not appropriately synchronized with pulses 317A, 317B of the x-ray
laser pulse signal 317. However, when the triggering signal 319 is
applied to the "water-in-oil" droplet stream by the electrodes 127,
the generation and release of sample suspension droplets 315C, 315D
are controllably synchronized with the pulses 317C, 317D of the
x-ray laser pulse signal 317. As a result, droplet 315C will reach
the optical path of the x-ray laser beam 303 at the same time as
the pulse 317C. Similarly, droplet 315D will be temporally
synchronized with pulse 317D and will reach the optical path of the
x-ray laser beam 303 at the same time as the pulse 317D. Further
details and examples of operating electrodes to apply a triggering
signal to synchronize droplets in a fluid stream with pulses of a
laser beam are described in International Patent Publication No. WO
2018/217831, entitled "METAL ELECTRODE BASED 3D PRINTED DEVICE FOR
TUNING MICROFLUIDIC DROPLET GENERATION FREQUENCY AND SYNCHRONIZING
PHASE FOR SERIAL FEMTOSECOND CRYSTALLOGRAPHY," the entire contents
of which are incorporated herein by reference.
[0031] FIGS. 4A through 4D illustrate a single-piece device 400
that provides electrode-based droplet generation with a T-junction
and electrodes in close proximity to a gas dynamic virtual nozzle
(GDVN) to inject a protein crystal sample for serial
crystallography. In this single-piece device 400, the droplet
triggering device and the gas dynamic virtual nozzle are integrated
into a single piece. In some implementations, the device 400 is
fabricated by 2-photon polymerization in a monolithic piece.
However, in other implementations, different 3D printing, molding,
or other fabrications techniques may be utilized. In some
implementations, as described in further detail below, silica
capillaries for liquid and gas delivery are coupled to the device
and gallium or silver-based non-contact metal electrodes embedded
into the 3D printed device are used to induce local electric fields
that change the water-in-oil interface and trigger the change of
droplet generation frequency. Droplets of aqueous crystal
suspension are generated in immiscible fluorinated oil in a
T-junction and are coaxially focused into a jet by helium gas in
the nozzle in one device component. In some implementations, the
droplet generation frequency can be modified from 10 Hz to 120 Hz
by controlling the flow rate ratios and synchronization is achieved
by applying the droplet generation trigger signal through the
embedded electrodes.
[0032] The single-piece device 400 in the example of FIGS. 4A
through 4D has six exterior surfaces arranged in a substantially
cuboid configuration: a rear surface 401, a front surface 402, a
first side surface 403, a second side surface 404, a top surface
405, and a bottom surface (not shown). The perspective of FIG. 4A
shows the rear surface 401, the first side surface 403, and the top
surface 405. The perspective of FIG. 4B shows the front surface
402, the first side surface 403, and the top surface 405. The
perspective of FIG. 4C shows the rear surface 401, the second side
surface 404, and the top surface 405. FIG. 4D is a
partially-transparent overhead view from the top surface 405 of the
device 400 to illustrate the interior channels and structures of
the device 400.
[0033] The rear surface 401 includes three channel opening inlets:
a first fluid inlet opening 411, a second fluid inlet opening 413,
and a gas inlet opening 415. The front surface 402 includes a
nozzle protrusion 421 and a nozzle opening 423. The nozzle
protrusion 421 is a tapered structure extending from the front
surface 402 and terminating at a peak where the nozzle opening 423
is positioned. The first side surface 403 includes a pair of
electrode openings 417, 419 and the second side surface 404 also
includes a pair of electrode openings 425, 427.
[0034] As shown in FIG. 4D, the first fluid inlet opening 411, the
second fluid inlet opening 413, and the gas inlet opening 415
extend into a body of the device 400 and are each configured to
receive a tube or capillary that will supply a fluid or gas to the
device 400. A gas channel 431 extends from the gas inlet opening
415 to an internal nozzle volume 433. The internal nozzle volume
433 is formed as a hollow chamber at least partially within the
nozzle protrusion 421 and opens to the nozzle opening 423.
Accordingly, pressurized air provided to the device 400 through the
gas inlet opening 423 moves through the gas channel 431 into the
internal nozzle volume 433 and exits the device 400 through the
nozzle opening 523.
[0035] The fluid droplet-generation channel 437 extends from the
first fluid inlet opening 411 towards a fluid outlet channel 439.
The fluid outlet channel is formed as a hollow protrusion into the
internal nozzle volume 433. The fluid outlet channel 439 includes
an opening at its distal end positioned proximate to the nozzle
opening 423. In some implementations, a first fluid (e.g., an oil
fluid) is pumped into the device through the first fluid inlet
opening 411, flows through the fluid droplet-generation channel 437
into the fluid outlet channel 439 where it is released towards the
nozzle opening 423. The distal end of the fluid outlet channel 439
is positioned relative to the gas channel 431 in the internal
nozzle volume 433 such that fluid exiting the fluid outlet channel
431 toward the nozzle opening 423 is coaxial with the pressurized
gas that is exiting the internal nozzle volume through the nozzle
opening 423. This coaxial arrangement with pressurized gas flow
surrounding the fluid stream in the same output direction results
in a "jetting" of the fluid stream through the nozzle opening
423.
[0036] A sample channel 435 is also formed within the device 400
coupling the second fluid inlet opening 413 to the fluid
droplet-generation channel 437. In the specific example of FIGS. 4A
through 4D, the first fluid inlet opening 411 and the second fluid
inlet opening 413 are formed on the same surface of the device 400
(i.e., the rear surface 401). Accordingly, the sample channel 435
includes a curved section to redirect the flow direction of fluid
through the sample channel 435 so that fluid from the sample
channel 435 enters the fluid droplet-generation channel 437 at an
angle. In the example of FIGS. 4A through 4D, the sample channel
435 meets the fluid droplet-generation channel 437 at a 90-degree
angle forming a T-junction.
[0037] The electrode openings 417, 419 on the first side surface
403 are coupled to each other by a first electrode internal volume
441. The first electrode internal volume 441 is positioned adjacent
to the fluid droplet-generation channel 437 and below the sample
channel 435 at the T-junction (i.e., the location where the sample
channel 435 meets the fluid droplet-generation channel 437. In this
example, one electrode opening 417 is larger than the other
electrode opening 419 on the first side surface 403. The larger
electrode opening 417 is also positioned slightly higher than the
smaller electrode opening 419 on the first side surface 403 (as
shown in FIG. 4A). The larger electrode opening 417 includes an
angled channel that extends over the sample channel 435 to a first
end of the first electrode internal volume 441. The smaller
electrode opening 419 also includes a channel that extends to the
opposite end of the first electrode internal volume 441. After the
device 400 is formed, a first electrode can be formed by filling
the first electrode internal volume 441 through one or both of the
electrode openings 417, 419 with a metal material. In some
implementations, wires are then extended through the electrode
openings 417, 419 to contact the deposited metal material in the
first electrode internal volume 441. Alternatively, in some
implementations, enough metal material is deposited to fill the
first electrode internal volume 441 and the channels of both
electrode openings 417, 419 so that a metal contact is created at
the exterior surface of the electrode openings 417, 419. In still
other implementations, an assembled/formed electrode component can
be inserted through one of the electrode openings 417, 419 in order
to position the electrode component adjacent to the
droplet-generation channel 437 in the first electrode internal
volume 441.
[0038] Similarly, the electrode openings 425, 427 on the second
side surface also each include a channel extending the opening to a
second electrode internal volume 443. The second electrode internal
volume 443 is formed adjacent to the droplet-generation channel 437
opposite the first electrode internal volume 443. A second metal
electrode may be positioned in the second electrode internal volume
443 by methods similar to those described above in reference to the
first electrode internal volume 441 (e.g., metal material
depositing or positioning an assembled/formed electrode device into
the second electrode internal volume 443 through one of the
electrode openings 425, 427).
[0039] FIGS. 4A through 4D illustrate one example of the device in
which the first electrode internal volume is positioned at the
T-junction below the sample channel 435. However, in other
implementations, the internal and external structures of the device
400 may be arranged differently. For example, FIGS. 5A, 5B, and 5C
illustrate another example of the device 400. The device 400 in
this example includes the same components and internal channels for
fluid and gas flow as in the example of FIGS. 4A through 4D.
However, in this example, the first electrode 503 is positioned
adjacent to the droplet-generation channel 437 above the sample
channel 435. The second electrode 501 is similarly placed adjacent
to the droplet-generation channel 437 opposite the first electrode
503. This placement of the first electrode 503 can be achieved, in
some implementations, by a different placement of the electrode
openings 417, 419 or by a different angle of the channels coupling
the electrode openings 417, 419 to the first electrode internal
volume 441. Alternatively, the first electrode internal volume 441
may be sized to include portions that are both above and below the
sample channel 435 such that the first electrode internal volume
surrounds the sample channel 435.
[0040] The device 400 is operated, in some implementations, based
on the systems and methods described above in reference to FIGS. 1
through 3B. A second fluid channel 102 (i.e., an "oil" channel) is
coupled to the first fluid inlet opening 411 by a capillary or tube
and a first fluid channel 101 (i.e., a sample channel) is coupled
to the second fluid inlet opening 413 by another capillary or tube.
Similarly, a pressurized helium gas source is coupled to the gas
inlet opening 415 by yet another capillary or tube. Oil pumped into
the first inlet opening 411 flows into and through the
droplet-generation channel 437 and droplets of the aqueous sample
suspension are introduced into the droplet-generation channel 437
from the sample channel 435. The size and frequency of the droplets
can be controlled by regulating operation of the fluid pumps to
adjust the fluid flow rates in the first fluid channel 101 and the
second fluid channel 102 as described above in reference to FIG. 2.
Furthermore, the droplets are then synchronized with the pulses of
the x-ray laser beam by applying a triggering signal to the fluid
in the droplet-generation channel through the electrodes positioned
in the first electrode internal volume 441 and the second electrode
internal volume 443.
[0041] By providing the droplet generation junction, the droplet
triggering electrodes, and the nozzle itself in a single piece
device, the total travel distance of the droplets is reduced (in
some implementations, to less than 1 cm). Single-piece devices such
as device 400 of FIGS. 4A through 4D are also compatible in
high-pressure systems and reduce complexity of the device &
experimental setup.
[0042] Thus, the invention provides, among other things, a
single-piece device for generating sample droplets in a
"water-in-oil" stream, synchronizing droplet frequency with a pulse
rate of a serial crystallography laser beam, and ejecting the
sample as a jetted stream. Other features and advantages of the
invention are set forth in the following claims.
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